[PATCH v6 4/5] drm/bridge: anx7625: add HDCP support

Xin Ji
2021-03-19T06:35:35Z

Add HDCP feature, enable HDCP function through chip internal key
and downstream's capability.

Signed-off-by: Xin Ji <xji@analogixsemi.com>
---
drivers/gpu/drm/bridge/analogix/anx7625.c | 147 ++++++++++++++++++++++
drivers/gpu/drm/bridge/analogix/anx7625.h | 36 ++++++
2 files changed, 183 insertions(+)

diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
index 8c514b46d361..b424a570effa 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.c
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
@@ -633,6 +633,150 @@ static int anx7625_dpi_config(struct anx7625_data *ctx)
return ret;
}

+static int anx7625_aux_dpcd_read(struct anx7625_data *ctx,
+ u8 addrh, u8 addrm, u8 addrl,
+ u8 len, u8 *buf)
+{
+ struct device *dev = &ctx->client->dev;
+ int ret;
+ u8 cmd;
+
+ if (len > MAX_DPCD_BUFFER_SIZE) {
+ DRM_DEV_ERROR(dev, "exceed aux buffer len.\n");
+ return -E2BIG;
+ }
+
+ cmd = ((len - 1) << 4) | 0x09;
+
+ /* Set command and length */
+ ret = anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+ AP_AUX_COMMAND, cmd);
+
+ /* Set aux access address */
+ ret |= anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+ AP_AUX_ADDR_7_0, addrl);
+ ret |= anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+ AP_AUX_ADDR_15_8, addrm);
+ ret |= anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+ AP_AUX_ADDR_19_16, addrh);
+
+ /* Enable aux access */
+ ret |= anx7625_write_or(ctx, ctx->i2c.rx_p0_client,
+ AP_AUX_CTRL_STATUS, AP_AUX_CTRL_OP_EN);
+
+ if (ret < 0) {
+ DRM_DEV_ERROR(dev, "cannot access aux related register.\n");
+ return -EIO;
+ }
+
+ usleep_range(2000, 2100);
+
+ ret = wait_aux_op_finish(ctx);
+ if (ret) {
+ DRM_DEV_ERROR(dev, "aux IO error: wait aux op finish.\n");
+ return ret;
+ }
+
+ ret = anx7625_reg_block_read(ctx, ctx->i2c.rx_p0_client,
+ AP_AUX_BUFF_START, len, buf);
+ if (ret < 0) {
+ DRM_DEV_ERROR(dev, "read dpcd register failed\n");
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static int anx7625_read_flash_status(struct anx7625_data *ctx)
+{
+ return anx7625_reg_read(ctx, ctx->i2c.rx_p0_client, R_RAM_CTRL);
+}
+
+static int anx7625_hdcp_key_probe(struct anx7625_data *ctx)
+{
+ int ret, val;
+ struct device *dev = &ctx->client->dev;
+ u8 ident[32];
+
+ ret = anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+ FLASH_ADDR_HIGH, 0x91);
+ ret |= anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+ FLASH_ADDR_LOW, 0xA0);
+ if (ret < 0) {
+ DRM_DEV_ERROR(dev, "IO error : set key flash address.\n");
+ return ret;
+ }
+
+ ret = anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+ FLASH_LEN_HIGH, (FLASH_BUF_LEN - 1) >> 8);
+ ret |= anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+ FLASH_LEN_LOW, (FLASH_BUF_LEN - 1) & 0xFF);
+ if (ret < 0) {
+ DRM_DEV_ERROR(dev, "IO error : set key flash len.\n");
+ return ret;
+ }
+
+ ret = anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+ R_FLASH_RW_CTRL, FLASH_READ);
+ ret |= readx_poll_timeout(anx7625_read_flash_status,
+ ctx, val,
+ ((val & FLASH_DONE) || (val < 0)),
+ 2000,
+ 2000 * 150);
+ if (ret) {
+ DRM_DEV_ERROR(dev, "flash read access fail!\n");
+ return -EIO;
+ }
+
+ ret = anx7625_reg_block_read(ctx, ctx->i2c.rx_p0_client,
+ FLASH_BUF_BASE_ADDR,
+ FLASH_BUF_LEN, ident);
+ if (ret < 0) {
+ DRM_DEV_ERROR(dev, "read flash data fail!\n");
+ return -EIO;
+ }
+
+ if (ident[29] == 0xFF && ident[30] == 0xFF && ident[31] == 0xFF)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int anx7625_hdcp_setting(struct anx7625_data *ctx)
+{
+ u8 bcap;
+ int ret;
+ struct device *dev = &ctx->client->dev;
+
+ ret = anx7625_hdcp_key_probe(ctx);
+ if (ret) {
+ DRM_DEV_DEBUG_DRIVER(dev, "disable HDCP by config\n");
+ return anx7625_write_and(ctx, ctx->i2c.rx_p1_client,
+ 0xee, 0x9f);
+ }
+
+ anx7625_aux_dpcd_read(ctx, 0x06, 0x80, 0x28, 1, &bcap);
+ if (!(bcap & 0x01)) {
+ DRM_DEV_DEBUG_DRIVER(dev, "bcap(0x%x) not support HDCP 1.4.\n",
+ bcap);
+ return anx7625_write_and(ctx, ctx->i2c.rx_p1_client,
+ 0xee, 0x9f);
+ }
+
+ DRM_DEV_DEBUG_DRIVER(dev, "enable HDCP 1.4\n");
+
+ ret = anx7625_write_or(ctx, ctx->i2c.rx_p1_client, 0xee, 0x20);
+
+ /* Try auth flag */
+ ret |= anx7625_write_or(ctx, ctx->i2c.rx_p1_client, 0xec, 0x10);
+ /* Interrupt for DRM */
+ ret |= anx7625_write_or(ctx, ctx->i2c.rx_p1_client, 0xff, 0x01);
+ if (ret < 0)
+ DRM_DEV_ERROR(dev, "fail to enable HDCP\n");
+
+ return ret;
+}
+
static void anx7625_dp_start(struct anx7625_data *ctx)
{
int ret;
@@ -643,6 +787,9 @@ static void anx7625_dp_start(struct anx7625_data *ctx)
return;
}

+ /* HDCP config */
+ anx7625_hdcp_setting(ctx);
+
if (ctx->pdata.is_dpi)
ret = anx7625_dpi_config(ctx);
else
diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.h b/drivers/gpu/drm/bridge/analogix/anx7625.h
index beee95da2155..c6f93e4df0ed 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.h
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.h
@@ -154,9 +154,45 @@

#define I2C_ADDR_7E_FLASH_CONTROLLER 0x7E

+#define FLASH_SRAM_SEL 0x00
+#define SRAM_ADDR_HIGH 0x01
+#define SRAM_ADDR_LOW 0x02
+#define SRAM_LEN_HIGH 0x03
+#define SRAM_LEN_LOW 0x04
#define FLASH_LOAD_STA 0x05
#define FLASH_LOAD_STA_CHK BIT(7)

+#define R_RAM_CTRL 0x05
+/* bit positions */
+#define FLASH_DONE BIT(7)
+#define BOOT_LOAD_DONE BIT(6)
+#define CRC_OK BIT(5)
+#define LOAD_DONE BIT(4)
+#define O_RW_DONE BIT(3)
+#define FUSE_BUSY BIT(2)
+#define DECRYPT_EN BIT(1)
+#define LOAD_START BIT(0)
+
+#define FLASH_ADDR_HIGH 0x0F
+#define FLASH_ADDR_LOW 0x10
+#define FLASH_LEN_HIGH 0x31
+#define FLASH_LEN_LOW 0x32
+
+#define R_FLASH_RW_CTRL 0x33
+/* bit positions */
+#define READ_DELAY_SELECT BIT(7)
+#define GENERAL_INSTRUCTION_EN BIT(6)
+#define FLASH_ERASE_EN BIT(5)
+#define RDID_READ_EN BIT(4)
+#define REMS_READ_EN BIT(3)
+#define WRITE_STATUS_EN BIT(2)
+#define FLASH_READ BIT(1)
+#define FLASH_WRITE BIT(0)
+
+#define FLASH_BUF_BASE_ADDR 0x60
+#define FLASH_BUF_LEN 0x20
+#define FLASH_KEY_OFFSET 0x8000
+
#define XTAL_FRQ_SEL 0x3F
/* bit field positions */
#define XTAL_FRQ_SEL_POS 5
--
2.25.1